Civil Engineer here. I actually do bulk shear testing on Municipal Solid Waste (read: landfill guts). Mining the landfills isn't something that we currently envision on the horizon, however we are interested in exactly how much load landfills can support, with the idea being to eventually build over them.

Seems logical that organic material would be burned off (possibly to generate energy, possibly just to get rid of it) and the metals smelted and re-used, doesn't it? Obviously whoever's doing it would have to do a content analysis to determine what they're burning and melting, but separating the various metals shouldn't be too hard with the metallurgical composition technologies we have. The other day I got to use a handheld scanner that you just hold up to a piece of metal and it scans it and tells you the exact composition by element (40% Cr, 52% Ni, .4% W, 3% Fe, etc.)

there was a post in the news recently about sweden buying other countries trash as their recycling is so profitable. I think with things like this going on it wont be long until people are mining old trash heaps.

I'm not sure that anyone will be able to pull usable goods out of landfills, but there's certainly a lot of materials locked away that could be put to use. Not to mention energy from organic wastes -- landfills are already releasing methane from anaerobic decomposition of organic substances.

I never even considered mining of landfills to be a possibility, but it definitely is an intriguing concept. I think this reality would only occur with exponential population growth and almost complete depletion of our natural resources. In other words, it would happen near the end of human civilization.

exponential population growth doesn't seem likely with current societal structures intact. Individuals living peacefully enough to support large population growth naturally limit their fertility. Resource depletion is real enough, but it won't come from exploding populations, but increased consumption.

plasmification would reduce the thing to elemental forms, that could then be separated in layers and siphoned out. as the artificial lightning cools back down it would naturally combine with whatever elements were around. syngas, a gasoline like hydrocarbon is actually easy to make this way... er, assuming you have the power requirements to heat things to plasma to begin with.

yep. it would destroy most complexities.

This would not be a good way to salvage wood. but a great way to salvage iron, gold, carbon, and all the other elements.